Black Hole

I am starting this thread for a place to ask questions that won't get buried as quickly in the regular discussion threads. Ask anything you want and if anybody knows hopefully you will get an answer.

I will start out with a question, perhaps Phil knows. Sometimes on twitter I see references of positive and negative mountain torque (MT) events. These occur over the Himalayan mountains and effect the weather downstream. Does anybody know exactly how these events are defined and what kinds of specific effects they cause in the midlatitudes? I suspect they can be seen on the angular momentum maps. Any help would be appreciated.

Phil

I am starting this thread for a place to ask questions that won't get buried as quickly in the regular discussion threads. Ask anything you want and if anybody knows hopefully you will get an answer.

I will start out with a question, perhaps Phil knows. Sometimes on twitter I see references of positive and negative mountain torque (MT) events. These occur over the Himalayan mountains and effect the weather downstream. Does anybody know exactly how these events are defined and what kinds of specific effects they cause in the midlatitudes? I suspect they can be seen on the angular momentum maps. Any help would be appreciated.

Ask your questions too!

It’s a mechanical exchange of angular momentum between the rotating Earth and the rotating atmosphere. Easy way to spot it is to follow the mean sea level pressure anomalies to the Lee of the Himalayas, and note whether the anomaly in the pressure gradient force there aligns or opposes the exchange induced by Earth’s rotation.

Example: Low pressures to the lee of the Himalayas produces a N—>S pressure gradient force, in opposition to the exchange w/ Earth’s rotation (which is E—>W) leading to a very modest slowdown. Since angular momentum must be conserved, the atmosphere rotates a bit faster, hence you get an extension of the east-Asian/NPAC jet, and often times a +PNA-type circulation following the peak in the double derivative of the anomaly (IE: following the fastest change in the AAM tendency).

And the climatological AAM background state changes on both short and long timescales, as the insolation gradients/seasonalities change w/ orbital cycles, ice sheets grow/retreat, etc. Even vacillations in the sign/seasonality of the annular modes/ITCZ can be either a derived function of, and/or conduit to, these exchanges of AAM. Many of the multidecadal climate cycles we talk about are expressed via changes in the structure of the AAM budget (which can amplify/dampen them via a slew of nonlinear/external modulators of the planetary energy budget..it’s very much an under-researched topic in climate change).

Black Hole

Posted 02 November 2018 - 11:28 AM

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It’s a mechanical exchange of angular momentum between the rotating Earth and the rotating atmosphere. Easy way to spot it is to follow the mean sea level pressure anomalies to the Lee of the Himalayas, and note whether the anomaly in the pressure gradient force there aligns or opposes the Earth’s rotation.

Example: Low pressures to the lee of the Himalayas produces an E—>W pressure gradient force, in opposition to the Earth’s rotation (W—>E) leading to a very modest slowdown. Since angular momentum must be conserved, the atmosphere rotates a bit faster, hence you get an extension of the east-Asian/NPAC jet, and often times a +PNA-type circulation following the peak in the double derivative of the anomaly (IE: following the fastest change in the AAM tendency).

And the climatological AAM background state changes on both short and long timescales, as the insolation gradients/seasonalities change w/ orbital cycles, ice sheets grow/retreat, etc. Even vacillations in the sign/seasonality of the annular modes/ITCZ can be either a derived function of, and/or conduit to, these exchanges of AAM. Many of the multidecadal climate cycles we talk about are expressed via changes in the structure of the AAM budget (which can amplify/dampen them via a slew of nonlinear/external modulators of the planetary energy budget..it’s very much an under-researched topic in climate change).

Good answer! Some follow up though. Taking the example of low pressure in the lee of the Himalayas you said that this induces an east->west pressure gradient. You didn't say anything about higher pressure to the east of the low, or any direction, so I am just curious why we assume an easterly pressure gradient is produced. You could just as well say a westerly gradient could be produced upstream as well. See what I mean? Can you elaborate more on that.

Next you talk about angular momentum conservation. Are you saying since the lower atmosphere sees a reduction in AAM that the atmosphere above it speeds up...or what? The rest makes sense and thanks again.

Edit - One other question. Typically I only think of mountains inducing lee side troughs. Are there ever reverse episodes of this which produce high pressure in the lee and contract the pacific jet?

Phil

Posted 02 November 2018 - 11:43 AM

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Good answer! Some follow up though. Taking the example of low pressure in the lee of the Himalayas you said that this induces an east->west pressure gradient. You didn't say anything about higher pressure to the east of the low, or any direction, so I am just curious why we assume an easterly pressure gradient is produced. You could just as well say a westerly gradient could be produced upstream as well. See what I mean? Can you elaborate more on that.

Next you talk about angular momentum conservation. Are you saying since the lower atmosphere sees a reduction in AAM that the atmosphere above it speeds up...or what? The rest makes sense and thanks again.

Blech, I meant to say south/north gradient force, not east/west. 😖 And it’s about the terrain itself setting the boundaries for the exchange. Hence the term “mountain torque”.

Black Hole

And it’s about the terrain itself setting the boundaries for the exchange. Hence the term “mountain torque”.

See my addition to the last post. But basically, depending on if you get north or south PGF affects if its a + or - MT event then correct? I would assume a South->North flow would transport higher AAM to the atmosphere and increase the jet extension if I am understanding.

wx_statman

Phil

Posted 02 November 2018 - 12:09 PM

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See my addition to the last post. But basically, depending on if you get north or south PGF affects if its a + or - MT event then correct? I would assume a South->North flow would transport higher AAM to the atmosphere and increase the jet extension if I am understanding.

Yeah, it’s about how it’s translated across the terrain. Sort of like how a spinning ballerina will spin faster if she pulls her arms in, or vice versa if she extends them. This is analogous to the rotating Earth and the spatial structure of the atmospheric mass (relative to the equilibrium point of the exchange rate).

It’s a hard concept to understand, let alone explain. At least for me.

Black Hole

Posted 02 November 2018 - 02:45 PM

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Yeah, it’s about how it’s translated across the terrain. Sort of like how a spinning ballerina will spin faster if she pulls her arms in, or vice versa if she extends them. This is analogous to the rotating Earth and the spatial structure of the atmospheric mass (relative to the equilibrium point of the exchange rate).

It’s a hard concept to understand, let alone explain. At least for me.

No worries, I know what AAM is so I just needed the concept explained in terms of the Himalayan specifics. You did great and I got it now.

iFred

Posted 03 November 2018 - 04:06 PM

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How strong is the siberian snow index to correlating to colder winters on this side of the Earth. I know this might be like someone asking a homeopathic question on WebMD, but seeing these brought up by legit mets on occasion makes me thing that there is some weight there.

Phil

Posted 03 November 2018 - 06:00 PM

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How strong is the siberian snow index to correlating to colder winters on this side of the Earth. I know this might be like someone asking a homeopathic question on WebMD, but seeing these brought up by legit mets on occasion makes me thing that there is some weight there.

I personally treat it like the PDO/blob. A reflector of a tendency rather than a cause. But I’m not well-versed on this one, admittedly.

Black Hole

Posted 04 November 2018 - 02:44 PM

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How strong is the siberian snow index to correlating to colder winters on this side of the Earth. I know this might be like someone asking a homeopathic question on WebMD, but seeing these brought up by legit mets on occasion makes me thing that there is some weight there.

What I know about this isn't a lot either...but I do know that the idea is that the more snow the more intense the surface cold that builds there. As a result the high pressure is stronger when there is more snow. Somehow or another this disrupts the polar vortex.

Jesse

Thanks. Yeah, it's part of my masters work. My thesis has two parts, 1) the lightning climatology in the west and 2) evaluating climate model projections for changes in said climatology.

Awesome. What are your overall findings? I was thinking maybe a northward expansion of activity associated with the SW monsoon in the warm season? Then perhaps more wintertime convection for places like here due to generally warmer surface temps.

wx_statman

Posted 05 November 2018 - 02:07 PM

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Awesome. What are your overall findings? I was thinking maybe a northward expansion of activity associated with the SW monsoon in the warm season? Then perhaps more wintertime convection for places like here due to generally warmer surface temps.

Well, I haven't gotten to climate model analysis yet. That's for next year. I'm only 7 months into a two-year program.

Everything I have done so far has been about quantifying 1988-2017 lightning climatology. Lots of interesting information, but nothing earth shattering you might say. The value lies in providing a methodical analysis. Overall, convection in Oregon and California is much more sensitive to transient moisture advection (at all levels) and steep lapse rates provided by passing cold troughs, compared to the core monsoon region. In places like AZ, NM, etc. you really only need the usual monsoonal moisture tap (which is a given in July & August most years). Strong daytime heating and orographic lifting provide the rest.

I've also dug up a whole bunch of interesting factoids. For example, the single most intense lightning storm from 1988-2017 in the western US (measured by total CG strikes in 24 hours over a 0.1 by 0.1 degree grid cell) was on June 5-6, 2015 in SE Montana. I dug around on Google and actually found a summary of that storm:

CraneWolf

Posted 05 November 2018 - 08:12 PM

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Hello, my name is CraneWolf, and I list geography, geology, climatology and meteorology highly among my list of favorite sciences. To that end, I have been creating an alternate Earth, with geographic and geological features different from Earth's but still inspired by them. The problem I have is that I know only the Cause--i.e. the changing of the geography--and not the Effect (how the changes in geography influence landscape, climate and weather). I have the whole description written down, but before I show you the description, if it is not too much trouble, would you be willing to help me with feedback and advice on the changes I had made? Thank you for your time.

wx_statman

Posted 06 November 2018 - 12:36 PM

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Hello, my name is CraneWolf, and I list geography, geology, climatology and meteorology highly among my list of favorite sciences. To that end, I have been creating an alternate Earth, with geographic and geological features different from Earth's but still inspired by them. The problem I have is that I know only the Cause--i.e. the changing of the geography--and not the Effect (how the changes in geography influence landscape, climate and weather). I have the whole description written down, but before I show you the description, if it is not too much trouble, would you be willing to help me with feedback and advice on the changes I had made? Thank you for your time.

This is probably too far-reaching of a question to throw out on an online forum. It's a bit like stopping someone on the street and asking them to explain the universe.

I recommend doing Google searches as well as looking up Youtube videos. So much information out there. You can find lecture notes from top-tier universities on just about any subject these days, simply by googling. I hope that helps.

CraneWolf

This is probably too far-reaching of a question to throw out on an online forum. It's a bit like stopping someone on the street and asking them to explain the universe.

I recommend doing Google searches as well as looking up Youtube videos. So much information out there. You can find lecture notes from top-tier universities on just about any subject these days, simply by googling. I hope that helps.

It would be hard (if not impossible) to answer without multidimensional computing. You need to include details like rotation rate, orbital cycles in precession/obliquity/eccentricity, atmospheric composition and density, all of the topographic details (including under the oceans, if there are any) and stuff like the age/type/distance of the star heating the planet, any moons/tidal forcings, magnetic fields, vulcanism, biology, etc. And it has to be exact both in terms of magnitude and evolution over time. Keep in mind that such a system might never reasonably equilibrate through time, so the state of the system may depend on its age just as much as the combination of the factors listed earlier.

CraneWolf

Posted 08 November 2018 - 06:09 AM

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Well, can you link a description of the planet in question?

It would be hard (if not impossible) to answer without multidimensional computing. You need to include details like rotation rate, orbital cycles in precession/obliquity/eccentricity, atmospheric composition and density, all of the topographic details (including under the oceans, if there are any) and stuff like the age/type/distance of the star heating the planet, any moons/tidal forcings, magnetic fields, vulcanism, biology, etc. And it has to be exact both in terms of magnitude and evolution over time. Keep in mind that such a system might never reasonably equilibrate through time, so the state of the system may depend on its age just as much as the combination of the factors listed earlier.

Ask, and ye shall receive. I got to warn you in advance--I hadn't done the ocean topography yet, but since you also asked for astronomy, this is going to be a bigger post than it already was. The atmosphere is the exact same (more or less.)

Alternate Earth 111, known colloquially as “Great Lakes Earth”, orbits the sun from a distance of 93 million miles. It itself is orbited by a single moon. Its equatorial diameter is 7,917.5 miles. 17% of its overall volume makes up its core. Its outer crust, rich in oxygen and silicon, is three miles at the thinnest and 30 at the thickest. It is the only planet in its system as far as we know that supports life. That’s pretty much the end of the similarities between Earth and AE111. There is a higher concentration of heavy elements--for example, Great Lakes Earth has 75 parts of gold per billion, as opposed to the four ppb we have back home.

One moon orbits Great Lakes Earth, just like back home, but beneath its rocky skin is a core of pure iron. It is the width of Callisto and orbits the planet from a distance of 382,240 miles.

The sun that Great Lakes Earth orbits is no different from ours—ten times the width of Jupiter, predominantly hydrogen and 10,000 degrees Fahrenheit at the surface. But this sun would find itself to be a crowded hub. The first planet orbits the sun from a distance of 1.4 million miles—26 times closer than our Mercury! But the wierdness doesn’t stop there. This Mercury is twice as wide as Earth and 8.63 times as massive. 42% of its volume consists of its core, which is made exclusively of iron and magnetic carbon. It completes one orbital revolution every 18 hours, but it is so tidally locked that one rotation can last 18 months. Extreme pressure from both within and without turns its purely carbonic crust into a massive plane of diamonds. Enough diamonds, in fact, to equal an estimate of 250 nonillion dollars.

Orbiting the sun from almost two million miles is the second planet in Solar System 111—Janus, named after the Trojan god of beginnings and endings and so named because the side facing the sun is as dry as Death Valley whereas the side facing away from the sun is a green liquid ocean. It can’t be water—not that close to the sun. As of today, we have yet to figure out what element Janus’s ocean is really made of. It is 6097 miles wide, three-quarters the width of Earth, yet has only 41% of its mass.

Orbiting 2.6 million miles from the sun, 92% the width of Earth and half as massive is Triton, a yellowish-purple ocean planet. Like Janus, the source of Triton’s liquid oceans remains a mystery.

Mimas, the fourth planet in Solar System 111, orbits the sun from a distance of three and a half million miles. It is 7500 miles wide and 68% as massive as Earth. What’s really exciting about this planet is that its crust consists of what astronomers calle “Ice X”, a kind of ice formed not from dropping temperature but from rising pressure. It seems the pressure may have been too much, as there is a hole of liquid iron the size of Africa.

Even more exciting is the fifth planet, Hyperborea, 8133 miles wide, 1.34 times more massive than Earth and orbiting the sun from a distance of 4.2 million miles. Its crust is made entirely of Ice VII, the original precursor to Ice X. No other alternate universe we have explored has foreign ice this close to an alternate Earth. Now the question scientists ask is—why is Hyperborea light green at the equator and dark green at the poles?

Three-quarters as wide and massive as Earth is the sixth planet, Golem, orbiting the sun from a distance of 5.6 million miles. Its core is made of pure iron and two-thirds the overall width. This combination makes for a strong magnetic field relative to its body size. Concealing the core is a plain plane of some kind of rock that can be found nowhere else in the solar system. Golem is still under active exploration.

To this day, we still don’t understand how Janus, Triton, Mimas, Hyperborea and Golem could be orbiting the sun so close to each other. There are many theories, but none of them are even remotely compelling—low magnetism, weak gravity, perhaps they are fragments of a once larger planet, or that they are not planets at all.

Venus orbits the sun from a distance of 36 million miles, a big difference compared to our Venus. An even bigger difference is size. Our Venus has a radius of 3760 miles — almost perfectly compatible with that of Earth’s 3959 — and a mass 82% that of Earth’s. In the solar system of Great Lakes Earth, Venus has a radius 175% wider than Earth and a mass five and a half times greater. 99% of the atmosphere is carbon dioxide, which isn’t much compared to the 96% our Venus has. But the remainder of our Venus’s atmosphere is nitrogen. The remainder of their Venus’s atmosphere is a greenhouse gas more potent than carbon dioxide—methane. This creates an atmospheric temperature of 1652 degrees Fahrenheit and a pressure of 1200 bars. Its global topography is nothing more than a vast, volcanically active plain, with lava eruptions oozing for centuries if not millennia. But the reason a planet this close to the sun still has an atmosphere is that the previous six planets block off most of the solar radiation emitted from the sun.

The next planet after Great Lakes Earth isn’t Mars, but what the people of Great Lakes Earth call “Neptune”. 2.6 times wider and seven times greater in mass than Earth, Neptune is a literal waterworld — a 30-mile-thick atmosphere of methane and water vapor conceals a chemical-rich ocean so extensive that land virtually does not exist. The global ocean is 160 miles deep before a mantle of silicate rock and a core of iron and sulfur. It orbits from the sun a distance of over 140 million miles, putting it in the same exact position that Mars has back home. What is most interesting about this Neptune is that it is more egg-shaped than spheroid. That is because it is in a tidal deadlock between two stars.

Back home, four giants orbit the sun. But in the solar system of Great Lakes Earth, there is only one—a brown dwarf star simply named Titan. At 165,074.66 miles, its width is almost twice that of Jupiter. However, it is 11 times more massive and surrounded by a ring system extending from 2500 to 25 million miles from its equator, which is at an axial tilt of 30 degrees. It also orbits the sun from a distance of 30 astronomical units.

Dark brown=mountains. Light brown=uplifts. Black=Igneous provinces still visible today at their original extent with no consideration of erosion.

The AmericasThe Appalachian Range used to exist, but all that remains nowadays are their metamorphic bedrocks. Since then, the Atlantic Coast is a labyrinth of islands, straits, channels and sounds, making New England the eastern equivalent of the Inside Passage, caused by five million years of being repeatedly scraped and bulldozed by ice. The terrain is not quite dramatic, the tallest above sea level being only 122.2 feet (37.25 meters.)

While our Rockies stand no taller than 14,440 feet above sea level, the tallest peak in a Great Lakes Rockies is measured to be 20,310 feet. Back home, our Rockies formed between 80 and 55 million years ago through the Laramide Orogeny, the subduction of the North American and Pacific plates at a shallow angle. Their Rockies first formed 55 million years ago as the result of a collision between eastern and western North America. They stopped becoming active as recently as nine million years ago. Since then, a series of faulting had shed off the mountains’ sedimentary skin and exposed the tougher granite-and-gneiss core. No wonder, then, that transdimensional explorer Mark Greene called the Great Lakes Earth Rockies “a single, continuous spine of breathtaking Tetons.” West of the Rockies stands an uplift varying in elevation above sea level between 2,000 and 13,000 feet (between 610 and 3962 meters.)

Minor differences in geological history could create major differences in geographical shape. Without the Cascades or the Alaska Range, the distinctively whiplike Alaskan Peninsula simply does not exist. The area we’d recognize as San Andreas (Baja Peninsula and southwestern California) is fused into what we’d call southeastern Alaska. Evidence in the rocks beneath the soil shows that San Andreas did indeed collide with Alaska only 24 million years ago, but the mountain-building period did not last long, and the peaks were reduced into quarter-mile-tall hills.

The Black Hills of South Dakota don’t exist on Great Lakes Earth. The Ozarks, larger in area and elevation than back home, are the closest analogy. The tallest stands 7242 feet (2207 meters) above sea level. They started life as a dome of granite that, over millions of years, had been replenished with fresh supplies of magma. This allowed the crystals that made the granite dramatically larger, making the rock itself a lot harder. After 2.2 billion years under the surface, the dome popped above sea level only as recently as 20 million years ago. Even though rain and river played a part in carving the dome into numerous spires, pillars and gorges, the real player in shaping the Ozarks is lower air pressure, exfoliating the surface into pieces like layers of onions.

True to the spirit of the planet’s name, North America is full of large lakes. The largest of which is Agassiz. In fact, it is the cornerstone of all of Great Lakes Earth’s great lakes — enormous depressions, tectonic rifts or volcanic calderas reshaped and filled in by ice, rain and river. To have an idea on the shape, size and scope of Agassiz, we must look at the familiar faces of the Great Lakes — Superior, Michigan, Huron, Erie and Ontario — and then flood off the entire basin. This is Lake Agassiz, 95,000 square miles and 5500 feet at its deepest. Agassiz started out as a series of rifts and faults that failed to split the continent. The valley wouldn’t become a lake until the ice bulldozed the depressions during the Pleistocene glaciations.

West of the Rockies, there are even more lakes—Bonneville, Carson, Olympia, Hamilton and Red Deer. All of them formed separately late during the Cenozoic as tectonic weaknesses sank the land, sometimes to the point below sea level. Further shaping the lakes were the last five million years of ice ages strengthening and weakening the freeze-thaw cycles. As a result, not only do they have their distinctive shapes, they are also deep. Bonneville, the deepest, is currently over a thousand feet deep.

What we’d presume to be the Brooks Range in northern Alaska actually isn’t. The Murchison Mountains, as we call them, are actually volcanic peaks standing 14,411 feet (4392 meters) above sea level at the tallest. They stand at one of the points where the Arctic Plate sinks beneath the Laurasian Plate.

The Yellowstone mantle plume is still present. Except that instead of Wyoming’s northwestern corner, it can be found in northeastern California. The upland itself covers an area of 5,000 square miles and stands almost like an island between the surrounding lakes and lowlands.

Five million years ago, the oceanic Panamanian Plate had been invaded on both fronts—by the Caribbean Plate in the northeast and the Pacific Plate in the southwest. This uplifted the basaltic slab to above sea level and had volcanoes guarding the plateau. The Twins, as they are called, are still active. One twin is currently 6,684 feet above sea level, the other 9,698 feet. Curiously, the Twins make up the coastline of Central America on Great Lakes Earth, which makes sense considering their young age. What doesn’t make sense is how they could be so tall in so short a time. The same problem is said of the Andes, which also make up South America’s entire western coastline. But if we look at a bathymetrical map, we start to understand why—from Argentina to Guatemala, the Pacific Plate is paralleled by the younger, narrower Nazca Plate. It first formed only ten million years ago and uplifted the Andean coastline for five million years before reaching the Panamanian Plate. This double-subduction may explain why the Andes, 25,122 feet above sea level and still rising, as they have been for the last 45 million years, had such devastating eruptions in the last 10,000 years, with an average of one eruption measuring eight on the VEI every thousand years.

Questions follow:

Are these changes enough to spare northeastern Nebraska from the onslaught of Tornado Alley without sacrificing the Midwest’s prairie fertility in the process?

Will all these lakes and rivers (not pictured) turn the Wild West into a greener Eden?

How much of the Amazon Basin will still be rainforest?

Eurasia Physically absent in the supercontinent are Turkey, Iran, and the Low Countries (Belgium, Netherlands, Luxemburg and Denmark). Back home, Scandinavia is one of Earth’s recognizable peninsulas. On Great Lakes Earth, the body we’d recognize as the Baltic Sea is actually known as the Baltic Plain.

The dominating feature of Asia is a large region of basaltic rock, the Siberian Traps. It formed as a series of eruptions spewed out lava 60 to 43 million years ago. Since most of northern Asia was a receding series of shallow seas at the time, the eruptions resulted in all four compositions of lava—low on both gas and viscosity, high on gas but low on viscosity, low on gas but high on viscosity and high on both gas and viscosity. However, 96% of those eruptions happened underwater, so they wouldn't react exactly like they would on land. Each eruption could last anywhere between 10,000 and 60,000 years, with breaks varying between 30,000 and 80,000 years. When the last eruption had finished, seven million square miles of Eurasia were buried under four million cubic miles of lava.

Eurasia is subject to Great Lakes Earth’s largest sea, one that we used to have back home — the Tethys. Back home, the Mediterranean has an average depth of 1500 meters and a maximum of 5267. The Tethys’ depth is 1205 meters on average and 7,000 maximum. Even so, the ratio between deep and shallow water is remarkably similar to that of the Mediterranean — more or less than 45% of the sea is no deeper than 200 meters (the required maximum depth for a sea to be “shallow”). It’s also connected to two oceans with two different personalities — the Indian to the east and the Atlantic to the west. What we’d recognize as the Arabian Peninsula is, on Great Lakes Earth, an extension of northeastern Africa, erasing both the Red Sea and the Gulf of Aden out of existence. This further widens the passage from the Indian Ocean to the Tethys.

The island of Newfoundland is the southeastern extension of Iceland. It stands at a point where a stationary mantle plume, loaded with silicon, stands at a crossroads between the Mid-Atlantic Ridge and the edge of the Arctic Plate. Unlike our Iceland, in which the Ridge has split it in east-west, the Iceland of Great Lakes Earth is split in a north-south division.

In Asia, what looks to us like Borneo is a big extension of eastern India, erasing the Bay of Bengal from the map. Sumatra is an extension of India’s western coast. The rest of Indonesia, as well as the island chain of the Philippines and the Malay Peninsula, don’t exist.

Back home, the Himalayan range in Asia is impressive enough. On Great Lakes Earth, they are even more so. The highest peak, Kailash, stands 33,500 feet (10,210.8 meters) above sea level and still rising. If the base of Mauna Kea in Hawaii were above sea level, this would have been its equal. Their Himalayas are older than ours, if the differences in height suggest anything. Ours first formed 50 million years ago. Theirs rose from the plains between 65 and 70 million years ago.

65 million years ago, sub-Himalayan Asia was subject to a series of lava eruptions lasting a total of 30,000 years. When it was all over, the lava covered a thickness exceeding one mile, an area of one-and-a-half million square miles and a volume greater than one million cubic miles.

The islands of Japan on Great Lakes Earth are the result of multiple faults and subductive hot spots, stationary mantle plumes standing in the intersections of colliding plates. Japan, consisting of six large hotspots, stands three miles southeast of the Laurasian Plate and five northwest of the Pacific Plate. The fact that the mountains make up the coastlines suggest that Japan on Great Lakes Earth formed very recently—no longer, it’s been surmised, than 11 million years. Like the Andes, Japan was subject to massive, earth-destroying eruptions.

The Alps remain tall, as they are back home. However, they are formed as the result of a piece of Africa, known to us as Balk, colliding with southeastern Europe 40 million years ago. Currently, the range’s highest peak, Olympus, stands 22,838 feet (6961 meters) above sea level and is still rising. Behind the Alps is a plateau that covers lands we’d recognize as Romania, Moldova, Slovenia, Austria, Slovakia and Hungary. Also, Balk’s terrain on Great Lakes Earth consists of plains and hills rather than mountain ranges like back home.

The Scandes, stretching the length of the northern Scandinavian coast, are the results of ocean/continent collisions — volcanoes. They are also taller than they are back home — 18,510 feet (5642 meters) above sea level and still rising.

The Ural, Caucasus, Pyrenees and Apennine mountain chains used to exist on Great Lakes Earth, but not anymore.

Questions follow:

With open connections to both the Indian and the Atlantic, what would the Tethys’s personality be?

Will a higher Himalayas — which means a higher Tibetan Plateau — pose any noticeable differences on India’s climate, precipitation and landscape?

Would adding Borneo and Sumatra pose any difference to the climate and landscape of the Indian subcontinent?

With the rest of Indonesia, the Philippines and the Malay Peninsula out of existence, how would this absence affect ocean currents?

How would all this added water affect the Mediterranean Basin as well as the Indian monsoon?

Concerning the Siberian Traps, 40 million years of erosion would mean an altogether different Russian landscape, no doubt, but to what extent? Would we still see vast, singular bands of boreal forests and steppes, or would we expect to see Russia hosting a wider variety of habitats?

Would a larger Deccan Traps pose any difference to the 65 million years of erosion?

How would the changes in mountain building and coastlining affect the climate and landscape of the rest of Europe?

AfricaLike some of the other continents, Africa has its share of great lakes — Chad, Congo and Makgadikgadi. Lake Makgadikgadi, the southernmost, is also the youngest—100 feet (30 meters) at the deepest and formed as water flowing from the Aden Bahçesi inundated a series of fault lines only three million years ago.

The Atlas Mountains used to exist on Great Lakes Earth, but not anymore.

The defining mountain range of Africa is the Aden Bahçesi, which first formed 45 million years ago as the Indian Plate sank beneath the African Plate. Currently, the tallest peak stands 21,810 feet (6647.7 meters) above sea level and still rising.

Lakes Chad and Congo had a shared history. They originated less than 200 million years ago as a series of horsts and grabens that would quickly be inundated aftewards. It wasn’t until 80 million years ago, when the seafloor slowed down and sea levels began to recede, that perhaps the deepest points on Great Lakes Earth during the Cretaceous period became surrounded by dry land. In time, freshwater diluted the lakes, pushing the salinity deeper and deeper. Today, Lake Congo to the south averages 221 meters deep, with a maximum of 2001 meters, the bottommost 15 feet being brine. Lake Chad to the north has an average depth of 337.5 meters with a maximum of 3791 meters, with the Pharaoh’s Brine taking up the bottom 20 meters.

Questions follow:

Are any of these changes enough to turn North and South Africa from desert to more verdant habitat, like savanna?

Would having a tropical megalake be enough to make a noticeable difference to the equatorial climate of the Congo rainforest?

AustraliaFirst and foremost, it’s not called “Australia” in Great Lakes Earth, but rather “Sahul”. The first major difference is the presence of Lake Eyre, a body of fresh water over 460,000 square miles in area and 49 meters at the deepest.

The northern and eastern coasts of Sahul are worth noticing. To the northwest, it looks as though the two main islands of New Zealand are glued into the mainland. It’d also look as though someone were shoving the island of New Guinea down the throat of mainland Australia, known geographically as the Gulf of Carpentaria. The northern and eastern extremes of Sahul are defined by volcanic mountains, the tallest standing 18,500 feet above sea level.

The final difference is that Sahul is much further south than Australia. So much so, in fact, that by comparison, the distance between it and Antarctica is cut by half.

Questions follow:

Will the Outback still be desert?

In the same scenario, Indonesia and the Philippines don’t exist. What kind of ocean current(s) would one expect to see influencing Sahul?

What kind of climatic and ecological influences would we expect Lake Eyre and the continent’s closer proximity to Antarctica to create?

Pole to PoleCompared to our oceans, the Arctic Ocean of Great Lakes Earth seems to have a little elbow room. The reason — the Atlantic on Great Lakes Earth is wider than ours by over 1350 miles. Africa, Eurasia and Sahul have, compared to our Old World, moved that far eastward, creating a landbridge that connects Asia to North America, erasing the Bering Strait off the map and shrinking the Bering Sea. To that extent, it would be like turning the Russian urban locality of Egvekinot (66.3205 degrees North and 179.1184 degrees West) into the next-door neighbor of Teller, Alaska. But that is in our eyes only. On Great Lakes Earth, North America has always been a part of Laurasia for 250 million years.

The island of Greenland looks, to us, rearranged to the extent that Mont Forel, the island’s highest peak, is located in 90 degrees North — the North Geographic Pole.

There is another difference, one that applies also to the Southern Ocean surrounding Antarctica. Back home, the Arctic’s average depth is only 1205 meters, whereas its deepest point is 5,625 meters. The Southern Ocean averages 4,000 meters deep and has a maximum depth of 7,235. On Great Lakes Earth, the Arctic averages 663 meters deep with a maximum of 7235 meters, whereas the Southern Ocean averages 2212 meters deep with a maximum depth of 5625 meters.

Then, of course, there is the Arctic Plate, something that doesn’t exist back home. Horizontally cutting Iceland in half, we can find the border straddling the coasts of Baffin Island, Alaska, and Scandinavia, creating the Scandes and the Murchison mountains.

Questions follow:

How would these differences affect ocean currents and polar landscapes?

Could any of these changes have influenced the global average temperature and precipitation? If so, to what extent?

Ocean DeepBack home, the Pacific Ocean, the largest of the five, has an average depth of 4028 meters and a maximum of 10,924 meters. On Great Lakes Earth, the Pacific’s depth averages 2025 meters and the maximum is now 8486 meters.

Back home, the Indian Ocean averages around 3963 meters deep with a maximum depth of 7258. On Great Lakes Earth, the Indian Ocean averages around 1467 meters deep and has a maximum depth of 7906 meters.

The Atlantic Ocean back home has an average depth of 3926 meters and a maximum of 8605 meters. On Great Lakes Earth, its average depth is now 1725 meters, and the maximum is now 10,911 meters, the same as the Pacific.

Questions follow:

How would the changes in depth affect ocean currents, therefore the global climate?

Jesse

Posted 08 November 2018 - 09:00 AM

Jesse

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<p>
Ask, and ye shall receive. I got to warn you in advance--I hadn't done the ocean topography yet, but since you also asked for astronomy, this is going to be a bigger post than it already was. The atmosphere is the exact same (more or less.)

Alternate Earth 111, known colloquially as “Great Lakes Earth”, orbits the sun from a distance of 93 million miles. It itself is orbited by a single moon. Its equatorial diameter is 7,917.5 miles. 17% of its overall volume makes up its core. Its outer crust, rich in oxygen and silicon, is three miles at the thinnest and 30 at the thickest. It is the only planet in its system as far as we know that supports life. That’s pretty much the end of the similarities between Earth and AE111. There is a higher concentration of heavy elements--for example, Great Lakes Earth has 75 parts of gold per billion, as opposed to the four ppb we have back home.

One moon orbits Great Lakes Earth, just like back home, but beneath its rocky skin is a core of pure iron. It is the width of Callisto and orbits the planet from a distance of 382,240 miles.

The sun that Great Lakes Earth orbits is no different from ours—ten times the width of Jupiter, predominantly hydrogen and 10,000 degrees Fahrenheit at the surface. But this sun would find itself to be a crowded hub. The first planet orbits the sun from a distance of 1.4 million miles—26 times closer than our Mercury! But the wierdness doesn’t stop there. This Mercury is twice as wide as Earth and 8.63 times as massive. 42% of its volume consists of its core, which is made exclusively of iron and magnetic carbon. It completes one orbital revolution every 18 hours, but it is so tidally locked that one rotation can last 18 months. Extreme pressure from both within and without turns its purely carbonic crust into a massive plane of diamonds. Enough diamonds, in fact, to equal an estimate of 250 nonillion dollars.

Orbiting the sun from almost two million miles is the second planet in Solar System 111—Janus, named after the Trojan god of beginnings and endings and so named because the side facing the sun is as dry as Death Valley whereas the side facing away from the sun is a green liquid ocean. It can’t be water—not that close to the sun. As of today, we have yet to figure out what element Janus’s ocean is really made of. It is 6097 miles wide, three-quarters the width of Earth, yet has only 41% of its mass.

Orbiting 2.6 million miles from the sun, 92% the width of Earth and half as massive is Triton, a yellowish-purple ocean planet. Like Janus, the source of Triton’s liquid oceans remains a mystery.

Mimas, the fourth planet in Solar System 111, orbits the sun from a distance of three and a half million miles. It is 7500 miles wide and 68% as massive as Earth. What’s really exciting about this planet is that its crust consists of what astronomers calle “Ice X”, a kind of ice formed not from dropping temperature but from rising pressure. It seems the pressure may have been too much, as there is a hole of liquid iron the size of Africa.

Even more exciting is the fifth planet, Hyperborea, 8133 miles wide, 1.34 times more massive than Earth and orbiting the sun from a distance of 4.2 million miles. Its crust is made entirely of Ice VII, the original precursor to Ice X. No other alternate universe we have explored has foreign ice this close to an alternate Earth. Now the question scientists ask is—why is Hyperborea light green at the equator and dark green at the poles?

Three-quarters as wide and massive as Earth is the sixth planet, Golem, orbiting the sun from a distance of 5.6 million miles. Its core is made of pure iron and two-thirds the overall width. This combination makes for a strong magnetic field relative to its body size. Concealing the core is a plain plane of some kind of rock that can be found nowhere else in the solar system. Golem is still under active exploration.

To this day, we still don’t understand how Janus, Triton, Mimas, Hyperborea and Golem could be orbiting the sun so close to each other. There are many theories, but none of them are even remotely compelling—low magnetism, weak gravity, perhaps they are fragments of a once larger planet, or that they are not planets at all.

Venus orbits the sun from a distance of 36 million miles, a big difference compared to our Venus. An even bigger difference is size. Our Venus has a radius of 3760 miles — almost perfectly compatible with that of Earth’s 3959 — and a mass 82% that of Earth’s. In the solar system of Great Lakes Earth, Venus has a radius 175% wider than Earth and a mass five and a half times greater. 99% of the atmosphere is carbon dioxide, which isn’t much compared to the 96% our Venus has. But the remainder of our Venus’s atmosphere is nitrogen. The remainder of their Venus’s atmosphere is a greenhouse gas more potent than carbon dioxide—methane. This creates an atmospheric temperature of 1652 degrees Fahrenheit and a pressure of 1200 bars. Its global topography is nothing more than a vast, volcanically active plain, with lava eruptions oozing for centuries if not millennia. But the reason a planet this close to the sun still has an atmosphere is that the previous six planets block off most of the solar radiation emitted from the sun.

The next planet after Great Lakes Earth isn’t Mars, but what the people of Great Lakes Earth call “Neptune”. 2.6 times wider and seven times greater in mass than Earth, Neptune is a literal waterworld — a 30-mile-thick atmosphere of methane and water vapor conceals a chemical-rich ocean so extensive that land virtually does not exist. The global ocean is 160 miles deep before a mantle of silicate rock and a core of iron and sulfur. It orbits from the sun a distance of over 140 million miles, putting it in the same exact position that Mars has back home. What is most interesting about this Neptune is that it is more egg-shaped than spheroid. That is because it is in a tidal deadlock between two stars.

Back home, four giants orbit the sun. But in the solar system of Great Lakes Earth, there is only one—a brown dwarf star simply named Titan. At 165,074.66 miles, its width is almost twice that of Jupiter. However, it is 11 times more massive and surrounded by a ring system extending from 2500 to 25 million miles from its equator, which is at an axial tilt of 30 degrees. It also orbits the sun from a distance of 30 astronomical units.

Dark brown=mountains. Light brown=uplifts. Black=Igneous provinces still visible today at their original extent with no consideration of erosion.

The Americas
The Appalachian Range used to exist, but all that remains nowadays are their metamorphic bedrocks. Since then, the Atlantic Coast is a labyrinth of islands, straits, channels and sounds, making New England the eastern equivalent of the Inside Passage, caused by five million years of being repeatedly scraped and bulldozed by ice. The terrain is not quite dramatic, the tallest above sea level being only 122.2 feet (37.25 meters.)

While our Rockies stand no taller than 14,440 feet above sea level, the tallest peak in a Great Lakes Rockies is measured to be 20,310 feet. Back home, our Rockies formed between 80 and 55 million years ago through the Laramide Orogeny, the subduction of the North American and Pacific plates at a shallow angle. Their Rockies first formed 55 million years ago as the result of a collision between eastern and western North America. They stopped becoming active as recently as nine million years ago. Since then, a series of faulting had shed off the mountains’ sedimentary skin and exposed the tougher granite-and-gneiss core. No wonder, then, that transdimensional explorer Mark Greene called the Great Lakes Earth Rockies “a single, continuous spine of breathtaking Tetons.” West of the Rockies stands an uplift varying in elevation above sea level between 2,000 and 13,000 feet (between 610 and 3962 meters.)

Minor differences in geological history could create major differences in geographical shape. Without the Cascades or the Alaska Range, the distinctively whiplike Alaskan Peninsula simply does not exist. The area we’d recognize as San Andreas (Baja Peninsula and southwestern California) is fused into what we’d call southeastern Alaska. Evidence in the rocks beneath the soil shows that San Andreas did indeed collide with Alaska only 24 million years ago, but the mountain-building period did not last long, and the peaks were reduced into quarter-mile-tall hills.

The Black Hills of South Dakota don’t exist on Great Lakes Earth. The Ozarks, larger in area and elevation than back home, are the closest analogy. The tallest stands 7242 feet (2207 meters) above sea level. They started life as a dome of granite that, over millions of years, had been replenished with fresh supplies of magma. This allowed the crystals that made the granite dramatically larger, making the rock itself a lot harder. After 2.2 billion years under the surface, the dome popped above sea level only as recently as 20 million years ago. Even though rain and river played a part in carving the dome into numerous spires, pillars and gorges, the real player in shaping the Ozarks is lower air pressure, exfoliating the surface into pieces like layers of onions.

True to the spirit of the planet’s name, North America is full of large lakes. The largest of which is Agassiz. In fact, it is the cornerstone of all of Great Lakes Earth’s great lakes — enormous depressions, tectonic rifts or volcanic calderas reshaped and filled in by ice, rain and river. To have an idea on the shape, size and scope of Agassiz, we must look at the familiar faces of the Great Lakes — Superior, Michigan, Huron, Erie and Ontario — and then flood off the entire basin. This is Lake Agassiz, 95,000 square miles and 5500 feet at its deepest. Agassiz started out as a series of rifts and faults that failed to split the continent. The valley wouldn’t become a lake until the ice bulldozed the depressions during the Pleistocene glaciations.

West of the Rockies, there are even more lakes—Bonneville, Carson, Olympia, Hamilton and Red Deer. All of them formed separately late during the Cenozoic as tectonic weaknesses sank the land, sometimes to the point below sea level. Further shaping the lakes were the last five million years of ice ages strengthening and weakening the freeze-thaw cycles. As a result, not only do they have their distinctive shapes, they are also deep. Bonneville, the deepest, is currently over a thousand feet deep.

What we’d presume to be the Brooks Range in northern Alaska actually isn’t. The Murchison Mountains, as we call them, are actually volcanic peaks standing 14,411 feet (4392 meters) above sea level at the tallest. They stand at one of the points where the Arctic Plate sinks beneath the Laurasian Plate.

The Yellowstone mantle plume is still present. Except that instead of Wyoming’s northwestern corner, it can be found in northeastern California. The upland itself covers an area of 5,000 square miles and stands almost like an island between the surrounding lakes and lowlands.

Five million years ago, the oceanic Panamanian Plate had been invaded on both fronts—by the Caribbean Plate in the northeast and the Pacific Plate in the southwest. This uplifted the basaltic slab to above sea level and had volcanoes guarding the plateau. The Twins, as they are called, are still active. One twin is currently 6,684 feet above sea level, the other 9,698 feet. Curiously, the Twins make up the coastline of Central America on Great Lakes Earth, which makes sense considering their young age. What doesn’t make sense is how they could be so tall in so short a time. The same problem is said of the Andes, which also make up South America’s entire western coastline. But if we look at a bathymetrical map, we start to understand why—from Argentina to Guatemala, the Pacific Plate is paralleled by the younger, narrower Nazca Plate. It first formed only ten million years ago and uplifted the Andean coastline for five million years before reaching the Panamanian Plate. This double-subduction may explain why the Andes, 25,122 feet above sea level and still rising, as they have been for the last 45 million years, had such devastating eruptions in the last 10,000 years, with an average of one eruption measuring eight on the VEI every thousand years.

Questions follow:

Are these changes enough to spare northeastern Nebraska from the onslaught of Tornado Alley without sacrificing the Midwest’s prairie fertility in the process?

Will all these lakes and rivers (not pictured) turn the Wild West into a greener Eden?

How much of the Amazon Basin will still be rainforest?

Eurasia
Physically absent in the supercontinent are Turkey, Iran, and the Low Countries (Belgium, Netherlands, Luxemburg and Denmark). Back home, Scandinavia is one of Earth’s recognizable peninsulas. On Great Lakes Earth, the body we’d recognize as the Baltic Sea is actually known as the Baltic Plain.

The dominating feature of Asia is a large region of basaltic rock, the Siberian Traps. It formed as a series of eruptions spewed out lava 60 to 43 million years ago. Since most of northern Asia was a receding series of shallow seas at the time, the eruptions resulted in all four compositions of lava—low on both gas and viscosity, high on gas but low on viscosity, low on gas but high on viscosity and high on both gas and viscosity. However, 96% of those eruptions happened underwater, so they wouldn't react exactly like they would on land. Each eruption could last anywhere between 10,000 and 60,000 years, with breaks varying between 30,000 and 80,000 years. When the last eruption had finished, seven million square miles of Eurasia were buried under four million cubic miles of lava.

Eurasia is subject to Great Lakes Earth’s largest sea, one that we used to have back home — the Tethys. Back home, the Mediterranean has an average depth of 1500 meters and a maximum of 5267. The Tethys’ depth is 1205 meters on average and 7,000 maximum. Even so, the ratio between deep and shallow water is remarkably similar to that of the Mediterranean — more or less than 45% of the sea is no deeper than 200 meters (the required maximum depth for a sea to be “shallow”). It’s also connected to two oceans with two different personalities — the Indian to the east and the Atlantic to the west. What we’d recognize as the Arabian Peninsula is, on Great Lakes Earth, an extension of northeastern Africa, erasing both the Red Sea and the Gulf of Aden out of existence. This further widens the passage from the Indian Ocean to the Tethys.

The island of Newfoundland is the southeastern extension of Iceland. It stands at a point where a stationary mantle plume, loaded with silicon, stands at a crossroads between the Mid-Atlantic Ridge and the edge of the Arctic Plate. Unlike our Iceland, in which the Ridge has split it in east-west, the Iceland of Great Lakes Earth is split in a north-south division.

In Asia, what looks to us like Borneo is a big extension of eastern India, erasing the Bay of Bengal from the map. Sumatra is an extension of India’s western coast. The rest of Indonesia, as well as the island chain of the Philippines and the Malay Peninsula, don’t exist.

Back home, the Himalayan range in Asia is impressive enough. On Great Lakes Earth, they are even more so. The highest peak, Kailash, stands 33,500 feet (10,210.8 meters) above sea level and still rising. If the base of Mauna Kea in Hawaii were above sea level, this would have been its equal. Their Himalayas are older than ours, if the differences in height suggest anything. Ours first formed 50 million years ago. Theirs rose from the plains between 65 and 70 million years ago.

65 million years ago, sub-Himalayan Asia was subject to a series of lava eruptions lasting a total of 30,000 years. When it was all over, the lava covered a thickness exceeding one mile, an area of one-and-a-half million square miles and a volume greater than one million cubic miles.

The islands of Japan on Great Lakes Earth are the result of multiple faults and subductive hot spots, stationary mantle plumes standing in the intersections of colliding plates. Japan, consisting of six large hotspots, stands three miles southeast of the Laurasian Plate and five northwest of the Pacific Plate. The fact that the mountains make up the coastlines suggest that Japan on Great Lakes Earth formed very recently—no longer, it’s been surmised, than 11 million years. Like the Andes, Japan was subject to massive, earth-destroying eruptions.

The Alps remain tall, as they are back home. However, they are formed as the result of a piece of Africa, known to us as Balk, colliding with southeastern Europe 40 million years ago. Currently, the range’s highest peak, Olympus, stands 22,838 feet (6961 meters) above sea level and is still rising. Behind the Alps is a plateau that covers lands we’d recognize as Romania, Moldova, Slovenia, Austria, Slovakia and Hungary. Also, Balk’s terrain on Great Lakes Earth consists of plains and hills rather than mountain ranges like back home.

The Scandes, stretching the length of the northern Scandinavian coast, are the results of ocean/continent collisions — volcanoes. They are also taller than they are back home — 18,510 feet (5642 meters) above sea level and still rising.

The Ural, Caucasus, Pyrenees and Apennine mountain chains used to exist on Great Lakes Earth, but not anymore.

Questions follow:

With open connections to both the Indian and the Atlantic, what would the Tethys’s personality be?

Will a higher Himalayas — which means a higher Tibetan Plateau — pose any noticeable differences on India’s climate, precipitation and landscape?

Would adding Borneo and Sumatra pose any difference to the climate and landscape of the Indian subcontinent?

With the rest of Indonesia, the Philippines and the Malay Peninsula out of existence, how would this absence affect ocean currents?

How would all this added water affect the Mediterranean Basin as well as the Indian monsoon?

Concerning the Siberian Traps, 40 million years of erosion would mean an altogether different Russian landscape, no doubt, but to what extent? Would we still see vast, singular bands of boreal forests and steppes, or would we expect to see Russia hosting a wider variety of habitats?

Would a larger Deccan Traps pose any difference to the 65 million years of erosion?

How would the changes in mountain building and coastlining affect the climate and landscape of the rest of Europe?

Africa
Like some of the other continents, Africa has its share of great lakes — Chad, Congo and Makgadikgadi. Lake Makgadikgadi, the southernmost, is also the youngest—100 feet (30 meters) at the deepest and formed as water flowing from the Aden Bahçesi inundated a series of fault lines only three million years ago.

The Atlas Mountains used to exist on Great Lakes Earth, but not anymore.

The defining mountain range of Africa is the Aden Bahçesi, which first formed 45 million years ago as the Indian Plate sank beneath the African Plate. Currently, the tallest peak stands 21,810 feet (6647.7 meters) above sea level and still rising.

Lakes Chad and Congo had a shared history. They originated less than 200 million years ago as a series of horsts and grabens that would quickly be inundated aftewards. It wasn’t until 80 million years ago, when the seafloor slowed down and sea levels began to recede, that perhaps the deepest points on Great Lakes Earth during the Cretaceous period became surrounded by dry land. In time, freshwater diluted the lakes, pushing the salinity deeper and deeper. Today, Lake Congo to the south averages 221 meters deep, with a maximum of 2001 meters, the bottommost 15 feet being brine. Lake Chad to the north has an average depth of 337.5 meters with a maximum of 3791 meters, with the Pharaoh’s Brine taking up the bottom 20 meters.

Questions follow:

Are any of these changes enough to turn North and South Africa from desert to more verdant habitat, like savanna?

Would having a tropical megalake be enough to make a noticeable difference to the equatorial climate of the Congo rainforest?

Australia
First and foremost, it’s not called “Australia” in Great Lakes Earth, but rather “Sahul”. The first major difference is the presence of Lake Eyre, a body of fresh water over 460,000 square miles in area and 49 meters at the deepest.

The northern and eastern coasts of Sahul are worth noticing. To the northwest, it looks as though the two main islands of New Zealand are glued into the mainland. It’d also look as though someone were shoving the island of New Guinea down the throat of mainland Australia, known geographically as the Gulf of Carpentaria. The northern and eastern extremes of Sahul are defined by volcanic mountains, the tallest standing 18,500 feet above sea level.

The final difference is that Sahul is much further south than Australia. So much so, in fact, that by comparison, the distance between it and Antarctica is cut by half.

Questions follow:

Will the Outback still be desert?

In the same scenario, Indonesia and the Philippines don’t exist. What kind of ocean current(s) would one expect to see influencing Sahul?

What kind of climatic and ecological influences would we expect Lake Eyre and the continent’s closer proximity to Antarctica to create?

Pole to Pole
Compared to our oceans, the Arctic Ocean of Great Lakes Earth seems to have a little elbow room. The reason — the Atlantic on Great Lakes Earth is wider than ours by over 1350 miles. Africa, Eurasia and Sahul have, compared to our Old World, moved that far eastward, creating a landbridge that connects Asia to North America, erasing the Bering Strait off the map and shrinking the Bering Sea. To that extent, it would be like turning the Russian urban locality of Egvekinot (66.3205 degrees North and 179.1184 degrees West) into the next-door neighbor of Teller, Alaska. But that is in our eyes only. On Great Lakes Earth, North America has always been a part of Laurasia for 250 million years.

The island of Greenland looks, to us, rearranged to the extent that Mont Forel, the island’s highest peak, is located in 90 degrees North — the North Geographic Pole.

There is another difference, one that applies also to the Southern Ocean surrounding Antarctica. Back home, the Arctic’s average depth is only 1205 meters, whereas its deepest point is 5,625 meters. The Southern Ocean averages 4,000 meters deep and has a maximum depth of 7,235. On Great Lakes Earth, the Arctic averages 663 meters deep with a maximum of 7235 meters, whereas the Southern Ocean averages 2212 meters deep with a maximum depth of 5625 meters.

Then, of course, there is the Arctic Plate, something that doesn’t exist back home. Horizontally cutting Iceland in half, we can find the border straddling the coasts of Baffin Island, Alaska, and Scandinavia, creating the Scandes and the Murchison mountains.

Questions follow:

How would these differences affect ocean currents and polar landscapes?

Could any of these changes have influenced the global average temperature and precipitation? If so, to what extent?

Ocean Deep
Back home, the Pacific Ocean, the largest of the five, has an average depth of 4028 meters and a maximum of 10,924 meters. On Great Lakes Earth, the Pacific’s depth averages 2025 meters and the maximum is now 8486 meters.

Back home, the Indian Ocean averages around 3963 meters deep with a maximum depth of 7258. On Great Lakes Earth, the Indian Ocean averages around 1467 meters deep and has a maximum depth of 7906 meters.

The Atlantic Ocean back home has an average depth of 3926 meters and a maximum of 8605 meters. On Great Lakes Earth, its average depth is now 1725 meters, and the maximum is now 10,911 meters, the same as the Pacific.

Questions follow:

How would the changes in depth affect ocean currents, therefore the global climate?

Black Hole

Extension, starting ~ D9. But a modest one (since we’re coming off a big-time retraction cycle). And trending poleward with time.

Will you take my chart and circle the areas you look for for the anomalies, and the path you see the air moving to enhance the AAM to extend the jet? If possible, for the -MT event too. I need to visualize this.

Front Ranger

Phil

Posted 08 November 2018 - 01:50 PM

Phil

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LocationCabin John, MD.

Hi, Cranewolf. That is one of the most fascinating and detailed thought-experiments I’ve ever seen.

Unfortunately, it is undoubtedly impossible to answer your question(s) without a relatively sophisticated computer model. There’s just so much that needs to be factored in and calculated. The human brain alone cannot do it.

Phil

Posted 08 November 2018 - 02:05 PM

Phil

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Members

21604 posts

LocationCabin John, MD.

Will you take my chart and circle the areas you look for for the anomalies, and the path you see the air moving to enhance the AAM to extend the jet? If possible, for the -MT event too. I need to visualize this.